"Sadness that begins in September–October and lifts in March–April" — this simple description is called Seasonal Affective Disorder (SAD). It is not "winter blues" — it is a clinical condition.
Statistically, in northern hemisphere countries, 1–10% of the population suffer from clinically significant SAD (the rate increases at higher latitudes). In countries at mid-latitudes, like Azerbaijan, symptoms also occur with considerable frequency.
SAD Symptoms
Several differences from classic depression:
- Excessive sleep (hypersomnia) — unlike typical depression
- Strong carbohydrate cravings — sweets, bread
- Weight gain (typical depression more often causes weight loss)
- Lethargy — a feeling of physical heaviness
- General depression symptoms (sadness, anhedonia, concentration difficulties)
Atypical seasonal variant: in some people, SAD begins in spring and lifts in autumn — this is less common.
Why Does This Happen?
Primary mechanisms:
1. Circadian rhythm disruption. Due to lack of sunlight in winter, the brain's internal clock is thrown off. Sleep-wake cycles shift.
2. Melatonin dysregulation. Darkness increases melatonin production — persistently high melatonin levels in winter cause fatigue and low mood.
3. Serotonin reduction. Lack of light reduces serotonin receptor activity. Serotonin is a mood regulator.
4. Vitamin D deficiency. Sunlight is needed to produce vitamin D. Vitamin D receptors are known to be present in brain areas that regulate mood.
Light Therapy — First-Line Treatment
Light therapy (phototherapy) is the most effective treatment for SAD. Research (Lam et al., 2016, meta-analysis): 60–80% of patients show significant improvement within 2–4 weeks.
How it works:
- A special lamp of 10,000 lux (no UV, white light)
- Daily in the morning for 30 minutes (within the first hour after waking)
- The lamp is positioned 50–60 cm from the face, slightly to the side
- During the session you can do other things (eating, reading, using a computer)
- Looking directly into the lamp is prohibited — it harms vision
When does the effect begin? Within 2–4 weeks. Symptoms reach their minimum at 6–8 weeks. Treatment should continue throughout winter.
Side Effects of Light Therapy
- Headache (10–15%)
- Eye strain
- Insomnia (if used in the evening)
- Triggering mania (risk in bipolar disorder)
Note: in people with a history of bipolar disorder, light therapy may trigger mania. Consultation with a psychiatrist is mandatory.
Other Treatment Methods
1. CBT (seasonal version). Focuses on seasonal thought patterns: "winter will never end," "I'll always be tired." Effectiveness is comparable to light therapy, but the effect after winter ends is more durable.
2. Antidepressants. SSRIs (especially bupropion) — in some cases started prophylactically from September.
3. Vitamin D supplements. Help when there is a vitamin D deficiency, but are not effective on their own for SAD.
4. Sleep hygiene. A regular sleep schedule, including on weekends, supports circadian rhythm stability.
5. Outdoor activity. Walks for 30–60 minutes during daylight hours even in winter have an antidepressant effect.
Practical Plan
- In September–October, purchase a light therapy lamp
- 30 minutes of light therapy every morning
- 30 minutes outdoors daily (during daylight hours)
- Vitamin D-3 1000–2000 IU/day (based on blood test results)
- Maintain a stable sleep schedule
- Limit carbohydrate consumption
- If symptoms worsen — see a psychiatrist
SAD is a seasonal condition that responds to treatment. An early and preventive approach makes winter significantly easier.